This invention relates to a dowel driving head device and a dowel driving machine for driving dowels into end surfaces of planks or square lumbers.
One arrangement based on the prior art is shown in FIG. 1. In FIG. 1, a shaft hole 2 is bored through a head 1 of a dowel driving head device in the front-rear direction (in right-left direction in the figure), and an ejection pipe 3 is attached to the front part of the shaft hole 2. A relay hole 4 of a large diameter intersecting the axis of the shaft hole 2 at right angles is formed behind the ejection pipe 3. A receiving hole 5 is formed above the relay hole 4 to meet the shaft hole 2 and the ejection pipe 3 from above at right angles. A chute 6 for supplying dowels D is connected to the top of the receiving hole 5.
A shaft for push-moving the dowel D forward (to the right) is slidably fit in the shaft hole 2. A delivery shaft 7 is rotatably fit in the axial part of the relay hole 4. A delivery hole 7a is bored in the delivery shaft 7 to intersect its axis at right angles. The dowel D supplied from the receiving hole 5 is fit in the delivery hole 7a. An adjustment screw 8 determines the position of the dowel D coming from the receiving hole 5 and fitting in the delivery hole 7a. 
As the delivery shaft 7 is rotated by 90 degrees about its axis, the dowel D supplied from the receiving hole 5 is rotated so that it is directed to the axes of the shaft hole 2 and the ejection pipe 3. In that state, as the shaft 9 is moved forward (right), the dowel D is ejected from the ejection pipe 3 forward and press-fit into the dowel hole H of the work located in front.
With the conventional arrangement, since a single head drives a single kind of dowels, in order to drive dowels of a different diameter for example, another head for that purpose must be provided in parallel, or components such as the ejection pipe 3, chute 6, and delivery shaft 7 must be replaced with those corresponding to the different diameter. This is disadvantageous because of increased size of the device and additional work for the replacement. This invention is arranged to provide a dowel driving head device and a dowel driving machine capable of driving more than one kinds of dowels using a single head without increasing/the size of the device.
The present invention has been made in view of the above problems. The present invention is arranged such that a single head is provided with a single shaft hole and a plurality of receiving holes, for individually receiving different kinds of dowels, arranged side by side in parallel, and that selection is made out of the different kinds of dowels of different diameters and lengths supplied from chutes to respective receiving holes.
As a result, different kinds of dowels can be driven easily without requiring extra work of changing a setup in spite of reducing the size of the device,
Various other advantages are obtainable according to various embodiments of the present invention.
One such advantage is that, since the stopper device is provided to hold and release the passage of the dowels in the respective receiving holes, selected dowels are driven in a stabilized manner.
Another advantage is that, since transfer passages are provided to interconnect the front parts of the receiving holes and the front part of the shaft hole, dowels of different lengths can be smoothly moved to the shaft hole while reducing the head size.
Furthermore, since guides for restricting the lateral movement of the dowels are detachably attached to parts of the transfer passages on the receiving holes side, dowels of different lengths can be fed to the shaft hole in a stabilized manner.
Also, since the inside diameter of the front end of the cylindrical main part as the ejection pipe is made slightly smaller than the diameter of the dowel and the front circumferential wall of the cylindrical main part is divided in the circumferential direction, the dowels of different diameters can be ejected accurately to the axis of the dowel hole.
Furthermore, since the attachment table is supported for vertical sliding to the X-axis movement table moving along the rear part of the surface table through the vertical direction guide rod, the attachment table can be moved in two axes with a simple structure. Since the attachment table is provided with the hole boring device, with the paste spouting nozzle, and with the dowel driving head device moving to and away from the dowel hole in the work in the direction crossing the dowel hole axis, a series of steps from forming the dowel hole to dowel driving can be performed quickly.